In some wireless networks, mobile stations (or subscriber stations) may occasionally switch to a low power or sleep mode. For example, a mobile station (MS) may negotiate with a base station (BS) to temporarily disrupt one or more wireless connections between the MS and the BS for a period of time known as a sleep window (which may last one or more frames, for example). During the sleep window, the BS does not schedule any downlink (DL) transmissions to the MS and the MS does not send any uplink (UL) transmissions to the BS, so that the MS may power down one or more hardware components required for communication in order to conserve power during the sleep window. For example, during a sleep window for a MS, the BS may buffer or drop arriving unicast packets associated with the MS (or associated with the MS's connection ID or user ID or MS ID), and may buffer any multicast packets for multicast transmission associated with a multicast ID for which the sleeping MS is a member. Each sleep window may typically be followed by a listening window in which the MS returns power to its required hardware components for communication and restores its one or more connections with the BS. During the listening window, any data buffered by the BS for the MS may then be transmitted to the MS and the MS may transmit UL to the BS. The MS may alternate between sleep and listening windows.